1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/fs.h>
21 #include <linux/mpage.h>
22 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/quotaops.h>
25 #include <linux/uio.h>
26 #include <linux/writeback.h>
27 #include "jfs_incore.h"
28 #include "jfs_inode.h"
29 #include "jfs_filsys.h"
30 #include "jfs_imap.h"
31 #include "jfs_extent.h"
32 #include "jfs_unicode.h"
33 #include "jfs_debug.h"
34 
35 
jfs_iget(struct super_block * sb,unsigned long ino)36 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
37 {
38 	struct inode *inode;
39 	int ret;
40 
41 	inode = iget_locked(sb, ino);
42 	if (!inode)
43 		return ERR_PTR(-ENOMEM);
44 	if (!(inode->i_state & I_NEW))
45 		return inode;
46 
47 	ret = diRead(inode);
48 	if (ret < 0) {
49 		iget_failed(inode);
50 		return ERR_PTR(ret);
51 	}
52 
53 	if (S_ISREG(inode->i_mode)) {
54 		inode->i_op = &jfs_file_inode_operations;
55 		inode->i_fop = &jfs_file_operations;
56 		inode->i_mapping->a_ops = &jfs_aops;
57 	} else if (S_ISDIR(inode->i_mode)) {
58 		inode->i_op = &jfs_dir_inode_operations;
59 		inode->i_fop = &jfs_dir_operations;
60 	} else if (S_ISLNK(inode->i_mode)) {
61 		if (inode->i_size >= IDATASIZE) {
62 			inode->i_op = &page_symlink_inode_operations;
63 			inode_nohighmem(inode);
64 			inode->i_mapping->a_ops = &jfs_aops;
65 		} else {
66 			inode->i_op = &jfs_fast_symlink_inode_operations;
67 			inode->i_link = JFS_IP(inode)->i_inline;
68 			/*
69 			 * The inline data should be null-terminated, but
70 			 * don't let on-disk corruption crash the kernel
71 			 */
72 			inode->i_link[inode->i_size] = '\0';
73 		}
74 	} else {
75 		inode->i_op = &jfs_file_inode_operations;
76 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
77 	}
78 	unlock_new_inode(inode);
79 	return inode;
80 }
81 
82 /*
83  * Workhorse of both fsync & write_inode
84  */
jfs_commit_inode(struct inode * inode,int wait)85 int jfs_commit_inode(struct inode *inode, int wait)
86 {
87 	int rc = 0;
88 	tid_t tid;
89 	static int noisy = 5;
90 
91 	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
92 
93 	/*
94 	 * Don't commit if inode has been committed since last being
95 	 * marked dirty, or if it has been deleted.
96 	 */
97 	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
98 		return 0;
99 
100 	if (isReadOnly(inode)) {
101 		/* kernel allows writes to devices on read-only
102 		 * partitions and may think inode is dirty
103 		 */
104 		if (!special_file(inode->i_mode) && noisy) {
105 			jfs_err("jfs_commit_inode(0x%p) called on read-only volume",
106 				inode);
107 			jfs_err("Is remount racy?");
108 			noisy--;
109 		}
110 		return 0;
111 	}
112 
113 	tid = txBegin(inode->i_sb, COMMIT_INODE);
114 	mutex_lock(&JFS_IP(inode)->commit_mutex);
115 
116 	/*
117 	 * Retest inode state after taking commit_mutex
118 	 */
119 	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
120 		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
121 
122 	txEnd(tid);
123 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
124 	return rc;
125 }
126 
jfs_write_inode(struct inode * inode,struct writeback_control * wbc)127 int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
128 {
129 	int wait = wbc->sync_mode == WB_SYNC_ALL;
130 
131 	if (inode->i_nlink == 0)
132 		return 0;
133 	/*
134 	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
135 	 * It has been committed since the last change, but was still
136 	 * on the dirty inode list.
137 	 */
138 	if (!test_cflag(COMMIT_Dirty, inode)) {
139 		/* Make sure committed changes hit the disk */
140 		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
141 		return 0;
142 	}
143 
144 	if (jfs_commit_inode(inode, wait)) {
145 		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
146 		return -EIO;
147 	} else
148 		return 0;
149 }
150 
jfs_evict_inode(struct inode * inode)151 void jfs_evict_inode(struct inode *inode)
152 {
153 	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
154 
155 	if (!inode->i_nlink && !is_bad_inode(inode)) {
156 		dquot_initialize(inode);
157 
158 		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
159 			struct inode *ipimap = JFS_SBI(inode->i_sb)->ipimap;
160 			truncate_inode_pages_final(&inode->i_data);
161 
162 			if (test_cflag(COMMIT_Freewmap, inode))
163 				jfs_free_zero_link(inode);
164 
165 			if (ipimap && JFS_IP(ipimap)->i_imap)
166 				diFree(inode);
167 
168 			/*
169 			 * Free the inode from the quota allocation.
170 			 */
171 			dquot_initialize(inode);
172 			dquot_free_inode(inode);
173 		}
174 	} else {
175 		truncate_inode_pages_final(&inode->i_data);
176 	}
177 	clear_inode(inode);
178 	dquot_drop(inode);
179 }
180 
jfs_dirty_inode(struct inode * inode,int flags)181 void jfs_dirty_inode(struct inode *inode, int flags)
182 {
183 	static int noisy = 5;
184 
185 	if (isReadOnly(inode)) {
186 		if (!special_file(inode->i_mode) && noisy) {
187 			/* kernel allows writes to devices on read-only
188 			 * partitions and may try to mark inode dirty
189 			 */
190 			jfs_err("jfs_dirty_inode called on read-only volume");
191 			jfs_err("Is remount racy?");
192 			noisy--;
193 		}
194 		return;
195 	}
196 
197 	set_cflag(COMMIT_Dirty, inode);
198 }
199 
jfs_get_block(struct inode * ip,sector_t lblock,struct buffer_head * bh_result,int create)200 int jfs_get_block(struct inode *ip, sector_t lblock,
201 		  struct buffer_head *bh_result, int create)
202 {
203 	s64 lblock64 = lblock;
204 	int rc = 0;
205 	xad_t xad;
206 	s64 xaddr;
207 	int xflag;
208 	s32 xlen = bh_result->b_size >> ip->i_blkbits;
209 
210 	/*
211 	 * Take appropriate lock on inode
212 	 */
213 	if (create)
214 		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
215 	else
216 		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
217 
218 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
219 	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
220 	    xaddr) {
221 		if (xflag & XAD_NOTRECORDED) {
222 			if (!create)
223 				/*
224 				 * Allocated but not recorded, read treats
225 				 * this as a hole
226 				 */
227 				goto unlock;
228 #ifdef _JFS_4K
229 			XADoffset(&xad, lblock64);
230 			XADlength(&xad, xlen);
231 			XADaddress(&xad, xaddr);
232 #else				/* _JFS_4K */
233 			/*
234 			 * As long as block size = 4K, this isn't a problem.
235 			 * We should mark the whole page not ABNR, but how
236 			 * will we know to mark the other blocks BH_New?
237 			 */
238 			BUG();
239 #endif				/* _JFS_4K */
240 			rc = extRecord(ip, &xad);
241 			if (rc)
242 				goto unlock;
243 			set_buffer_new(bh_result);
244 		}
245 
246 		map_bh(bh_result, ip->i_sb, xaddr);
247 		bh_result->b_size = xlen << ip->i_blkbits;
248 		goto unlock;
249 	}
250 	if (!create)
251 		goto unlock;
252 
253 	/*
254 	 * Allocate a new block
255 	 */
256 #ifdef _JFS_4K
257 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
258 		goto unlock;
259 	rc = extAlloc(ip, xlen, lblock64, &xad, false);
260 	if (rc)
261 		goto unlock;
262 
263 	set_buffer_new(bh_result);
264 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
265 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
266 
267 #else				/* _JFS_4K */
268 	/*
269 	 * We need to do whatever it takes to keep all but the last buffers
270 	 * in 4K pages - see jfs_write.c
271 	 */
272 	BUG();
273 #endif				/* _JFS_4K */
274 
275       unlock:
276 	/*
277 	 * Release lock on inode
278 	 */
279 	if (create)
280 		IWRITE_UNLOCK(ip);
281 	else
282 		IREAD_UNLOCK(ip);
283 	return rc;
284 }
285 
jfs_writepage(struct page * page,struct writeback_control * wbc)286 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
287 {
288 	return block_write_full_page(page, jfs_get_block, wbc);
289 }
290 
jfs_writepages(struct address_space * mapping,struct writeback_control * wbc)291 static int jfs_writepages(struct address_space *mapping,
292 			struct writeback_control *wbc)
293 {
294 	return mpage_writepages(mapping, wbc, jfs_get_block);
295 }
296 
jfs_readpage(struct file * file,struct page * page)297 static int jfs_readpage(struct file *file, struct page *page)
298 {
299 	return mpage_readpage(page, jfs_get_block);
300 }
301 
jfs_readpages(struct file * file,struct address_space * mapping,struct list_head * pages,unsigned nr_pages)302 static int jfs_readpages(struct file *file, struct address_space *mapping,
303 		struct list_head *pages, unsigned nr_pages)
304 {
305 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
306 }
307 
jfs_write_failed(struct address_space * mapping,loff_t to)308 static void jfs_write_failed(struct address_space *mapping, loff_t to)
309 {
310 	struct inode *inode = mapping->host;
311 
312 	if (to > inode->i_size) {
313 		truncate_pagecache(inode, inode->i_size);
314 		jfs_truncate(inode);
315 	}
316 }
317 
jfs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)318 static int jfs_write_begin(struct file *file, struct address_space *mapping,
319 				loff_t pos, unsigned len, unsigned flags,
320 				struct page **pagep, void **fsdata)
321 {
322 	int ret;
323 
324 	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
325 				jfs_get_block);
326 	if (unlikely(ret))
327 		jfs_write_failed(mapping, pos + len);
328 
329 	return ret;
330 }
331 
jfs_bmap(struct address_space * mapping,sector_t block)332 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
333 {
334 	return generic_block_bmap(mapping, block, jfs_get_block);
335 }
336 
jfs_direct_IO(struct kiocb * iocb,struct iov_iter * iter)337 static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
338 {
339 	struct file *file = iocb->ki_filp;
340 	struct address_space *mapping = file->f_mapping;
341 	struct inode *inode = file->f_mapping->host;
342 	size_t count = iov_iter_count(iter);
343 	ssize_t ret;
344 
345 	ret = blockdev_direct_IO(iocb, inode, iter, jfs_get_block);
346 
347 	/*
348 	 * In case of error extending write may have instantiated a few
349 	 * blocks outside i_size. Trim these off again.
350 	 */
351 	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
352 		loff_t isize = i_size_read(inode);
353 		loff_t end = iocb->ki_pos + count;
354 
355 		if (end > isize)
356 			jfs_write_failed(mapping, end);
357 	}
358 
359 	return ret;
360 }
361 
362 const struct address_space_operations jfs_aops = {
363 	.readpage	= jfs_readpage,
364 	.readpages	= jfs_readpages,
365 	.writepage	= jfs_writepage,
366 	.writepages	= jfs_writepages,
367 	.write_begin	= jfs_write_begin,
368 	.write_end	= nobh_write_end,
369 	.bmap		= jfs_bmap,
370 	.direct_IO	= jfs_direct_IO,
371 };
372 
373 /*
374  * Guts of jfs_truncate.  Called with locks already held.  Can be called
375  * with directory for truncating directory index table.
376  */
jfs_truncate_nolock(struct inode * ip,loff_t length)377 void jfs_truncate_nolock(struct inode *ip, loff_t length)
378 {
379 	loff_t newsize;
380 	tid_t tid;
381 
382 	ASSERT(length >= 0);
383 
384 	if (test_cflag(COMMIT_Nolink, ip)) {
385 		xtTruncate(0, ip, length, COMMIT_WMAP);
386 		return;
387 	}
388 
389 	do {
390 		tid = txBegin(ip->i_sb, 0);
391 
392 		/*
393 		 * The commit_mutex cannot be taken before txBegin.
394 		 * txBegin may block and there is a chance the inode
395 		 * could be marked dirty and need to be committed
396 		 * before txBegin unblocks
397 		 */
398 		mutex_lock(&JFS_IP(ip)->commit_mutex);
399 
400 		newsize = xtTruncate(tid, ip, length,
401 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
402 		if (newsize < 0) {
403 			txEnd(tid);
404 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
405 			break;
406 		}
407 
408 		ip->i_mtime = ip->i_ctime = current_time(ip);
409 		mark_inode_dirty(ip);
410 
411 		txCommit(tid, 1, &ip, 0);
412 		txEnd(tid);
413 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
414 	} while (newsize > length);	/* Truncate isn't always atomic */
415 }
416 
jfs_truncate(struct inode * ip)417 void jfs_truncate(struct inode *ip)
418 {
419 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
420 
421 	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
422 
423 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
424 	jfs_truncate_nolock(ip, ip->i_size);
425 	IWRITE_UNLOCK(ip);
426 }
427